Hello Amman. A common misconception among consumers is that after laser hair removal all the hair falls out immediately. This is not necessarily the case, especially at the beginning of the treatment program when lower settings are being used to ensure safe treatments.
In some cases during laser hair removal, the base (bulb) of the hair follicle will achieve a high enough temperature so as to dislodge the hair from it's base and it will fall out. In other cases where this temperature is not reached, the hair continues to grow. It is only over the course of several treatments that the small blood vessels at the base of the hair follicle cease to function as a result of heat damage and this is when the hair falls out and does not grow back.